JP2000080223A - Thermoplastic polyester resin composition and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic polyester resin composition excellent in flexibility not reducing mechanical strength and heat resistance as compared with conventional thermoplastic polyester elastomer while maintaining moldability, releasability and the method manufacturing the same. SOLUTION: This composition comprises formulation of (C) 1 to 20 pts.wt. of an olefinic copolymer at least including a (meth)arylate component having epoxy group in the molecule, (D) 1 to 20 pts.wt. of paraffinic oil component and (E) 0.1 to 2.0 pts.wt. of a cross-linking initiator compounded in 100 pts.wt. of a composition comprising (A) 75 to 5 pts.wt. of a random copolyester resin and (B) 25 to 95 pts.wt. of EPDM rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a thermoplastic polyester resin composition and a method for producing the same.
More specifically, by dispersing a specific crosslinked rubber component in a random-type copolymerized polyester resin, it is possible to realize an elastomer that is more flexible than a conventional block-type thermoplastic polyester elastomer, and at the same time, has good moldability and releasability. To expand the field of application to applications such as molded products that were advantageous for conventional rubber products, such as various packings, hoses, telephone wire curl cords, cable covers, bottle stoppers, golf ball skin materials, etc. The present invention relates to a thermoplastic polyester resin composition and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, thermoplastic polyester elastomers (hereinafter referred to as "TPEE") have been used in a wide range of fields because of their good moldability, heat aging resistance and chemical resistance. This TPEE is usually a block-type copolymer composition, so it is known to increase the high-melting polyester segment (hard segment) component in order to increase the mechanical strength.
There is a disadvantage that the flexibility of the resin is poor.
On the other hand, in order to impart flexibility to the TPEE, it is known to increase the number of low-melting polyester or polyether segment (soft segment) components. There was a problem that the target strength was reduced. Further, in the case of a conventional block type TPEE having a copolymer composition, there is a limit in reducing the hardness and the elastic modulus, and the price is high. Therefore, attempts have been made to add amorphous polymers typified by rubber to block-type TPEE and crystalline polyesters such as polyethylene terephthalate and polybutylene terephthalate.However, due to poor compatibility, There was a problem that a product having the required elastomer properties could not be obtained.

On the other hand, there has been proposed a method of obtaining a thermoplastic elastomer composition by so-called dynamic crosslinking in which a crystalline polyester and an EPDM rubber are kneaded at a high shear rate and crosslinked with a crosslinking agent (Japanese Patent Publication No. 55-14099). No.). However, since crystalline polyester and EPDM rubber are originally incompatible with each other, it is extremely difficult to obtain a uniform and stable microstructure composition by mechanical kneading alone, and the obtained composition is There was a problem that the mechanical properties were insufficient and the product was not practical. Further, as an attempt to solve these problems, a method of improving the compatibility between the crystalline polyester and the EPDM rubber by adding an ethylene acrylic rubber having a polar group capable of reacting with the terminal group of the crystalline polyester as a third component. Has been proposed (JP-A-8-302112). However, since the ethylene acrylic rubber used in this method has a large adhesive property, there is a problem in mold release properties and the like in producing a thermoplastic elastomer.

[0004]

According to the present invention, a rubber component is dispersed in a random copolymerized polyester, and the dispersion is not only caused by mechanical kneading, but also by an olefin system having a reactive group as a third component. The copolymer reacts with the terminal group of the random copolymerized polyester to improve the compatibility between the random copolymerized polyester and the rubber component, and at the same time, performs internal crosslinking of the rubber component in the presence of a crosslinking initiator. By doing so, thermoplastic polyester with excellent flexibility, while maintaining moldability and releasability, without lowering mechanical strength and heat resistance than conventional TPEE, and by adding a specific oil An object of the present invention is to provide a resin composition and a method for producing the same.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have completed the present invention. That is, the gist of the present invention is as follows. (1) (A) 75 to 5 parts by weight of random type copolyester resin and (B) 25 to 95 parts by weight of EPDM rubber. Olefin copolymers having at least an acrylate component 1 to 20
Parts by weight, (D) 1 to 20 parts by weight of paraffinic oil and (E)
A thermoplastic polyester resin composition comprising 0.1 to 2.0 parts by weight of a crosslinking initiator. (2) The olefin copolymer of the component (C) is ethylene / glycidyl (meth) acrylate copolymer, propylene / glycidyl (meth) acrylate copolymer, ethylene / glycidyl (meth) acrylate / vinyl acetate ternary Copolymer, propylene / glycidyl (meth) acrylate /
The thermoplastic polyester according to the above (1), comprising an olefin copolymer selected from the group consisting of a vinyl acetate terpolymer, ethylene / propylene / glycidyl (meth) acrylate / vinyl acetate quaternary copolymer. Resin composition. (3) The weight average molecular weight of the paraffinic oil of the component (D) is
The thermoplastic polyester resin composition according to the above (1), wherein the composition is in the range of 300 to 730. (4) (A) random copolymerized polyester resin, (B) EPDM rubber, (C) olefin copolymer having at least an epoxy-containing (meth) acrylate component in the same molecule, and
(D) Melt and knead paraffinic oil, (A) component and (C)
A method for producing a thermoplastic polyester resin composition, comprising reacting a component with a component, adding a crosslinking initiator (E), and internally kneading the component (B) by melt-kneading.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The random copolymerized polyester resin as the component (A) used in the present invention includes terephthalic acid,
Aromatic dicarboxylic acid components such as isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, 4,4'-sulfonyldibenzoic acid, adipic acid, and azelaic acid , An aliphatic dicarboxylic acid component such as sebacic acid and ethylene glycol,
Propylene glycol, tetramethylene glycol, pentamethylene glycol, 2,2-dimethyltrimethylene glycol, hexamethylene glycol, decamethylene glycol, p-xylene glycol, cyclohexanedimethanol, poly (ethylene oxide) glycol, poly (1,2-propylene A random copolymerized polyester comprising a diol component such as (oxide) glycol, poly (1,3-propylene oxide) glycol, poly (tetramethylene oxide) glycol, or a lactone such as ε-caprolactone or δ-pivalolactone; A random copolymerized polyester of a dicarboxylic acid component and the diol component, an aromatic ether dicarboxylic acid component such as 1,4-bis (4,4′-dicarboxydiphenoxy) ethane, and the diol component. That such random copolymer polyesters.

The relative viscosity of the above random copolymerized polyester is determined by using a mixed solvent of phenol / 1,1,1,2,2-tetrachloroethane (weight ratio 1/1) at a temperature of 20.
It is preferably in the range of 1.2 to 2.5 when measured at a temperature of 0.5 ° C. and a concentration of 0.5 g / dl. The melting point of the random copolymerized polyester is usually in the range of 140 to 250 ° C, but preferably 150 to 200 ° C. Further, the acid value (the number of COOH groups) of the random copolymerized polyester is preferably in the range of 30 to 120 eq / t as determined by terminal group titration.

EPDM of component (B) used in the present invention
The rubber includes a terpolymer of ethylene, propylene and a non-conjugated diene. Further, the non-conjugated diene constituting the terpolymer is 5-ethylidene-2.
-Norbornene, 1,4-hexadiene, 5-methylene-2-norbornene, 1,6-octadiene, 2-methyl-1,4-pentadiene, 5-methyl-1,4-hexadiene, 3,7-dimethyl-
Examples include 1,6-octadiene, 1,3-cyclopentadiene, 1,4-cyclohexadiene, dicyclopentadiene, 1,5-cyclooctadiene, 1-methyl-1,5-cyclooctadiene, and the like.

The olefin copolymer as the component (C) used in the present invention is a polymer compound which exhibits a substantially amorphous state at room temperature, is a thermoplastic and uncrosslinked one, and has a high temperature. (150 ° C. or higher) does not thermally and rapidly crosslink, and contains an epoxy group as a reactive functional group.

Specific examples of the olefin copolymer include a copolymer having an epoxy-containing (meth) acrylate component in the same molecule or a terpolymer having an epoxy-containing (meth) acrylate component and a vinyl acetate component in the same molecule. Copolymers and quaternary copolymers, preferably ethylene / glycidyl (meth) acrylate copolymer, propylene / glycidyl (meth) acrylate copolymer, ethylene / glycidyl (meth) acrylate / vinyl acetate terpolymer Copolymer, propylene / glycidyl (meth) acrylate / vinyl acetate terpolymer, ethylene / propylene / glycidyl (meth) acrylate / vinyl acetate quaternary copolymer, etc. Terpolymers or quaternary copolymers are particularly preferred because of their excellent flexibility. Arbitrariness.

The paraffinic oil used as the component (D) in the present invention has an action of swelling the EPDM rubber of the component (B), and is not particularly limited as long as it has low toxicity. Those having an average molecular weight in the range of 300 to 730 are preferred. When the weight-average molecular weight is less than 300, the boiling point is low, the oil volatilizes severely during melt-kneading, and the flexibility is reduced. If the weight average molecular weight exceeds 730, the viscosity of the oil is high and the fluidity is inferior, so that a problem is likely to occur in the quantitative addition to the kneader.

The crosslinking initiator used as the component (E) in the present invention is not particularly limited as long as it can be crosslinked at the unsaturated bond site of the EPDM rubber. Specific examples thereof include sulfur, acetyl peroxide, succinic acid peroxide, benzoyl peroxide, m-toluyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, (T-butylperoxy) cyclohexane, t-butylperoxyisopropyl carbonate, 2,2-bis (t-butylperoxy) octane, t-butylperoxyacetate, 2,5-dimethyl-2,5-di (benzoylperoxy) Hexane, t-butylperoxylaurate, di-t-butylperoxyisophthalate, t-butylperoxybenzene, dicumyl peroxide, α,
α'-bis (t-butylperoxy-m-isopropyl) benzene, t-butylcumyl peroxide, 2,5-dimethyl-2,5
-Di (t-butylperoxy) hexane, di-t-butylperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl Organic peroxides such as hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide are included.

In the composition of the present invention, the above (A) and (A)
The amount of component (B) should be 75 to 5 parts by weight for component (A) and 25 to 95 parts by weight for component (B). (A) component
If it exceeds 75 parts by weight, the flexibility tends to decrease. On the other hand, if the amount of the component (A) is less than 5 parts by weight, the component (A) can no longer be a continuous phase, and melt molding becomes difficult. The amount of the component (C) must be 1 to 20 parts by weight based on 100 parts by weight of the total of the components (A) and (B). If the amount of the component (C) is less than 1 part by weight, the reaction with the terminal carboxyl group of the component (A) does not proceed sufficiently, and the component (A) does not play a sufficient role as a compatibilizer. The interfacial adhesion of the components becomes insufficient, and physical properties such as mechanical properties tend to decrease. On the other hand, when the component (C) exceeds 20 parts by weight, the mechanical properties hardly improve, only the cost increases, and the surface of the molded article tends to become tacky. The amount of the component (D) must be 1 to 20 parts by weight based on 100 parts by weight of the total of the components (A) and (B). When the amount of the component (D) is less than 1 part by weight, it does not sufficiently serve as a plasticizer for rubber because of a small amount, and cannot provide sufficient flexibility to the obtained thermoplastic resin composition. On the other hand, when the component (D) exceeds 20 parts by weight, the tensile strength of the obtained thermoplastic resin composition is remarkably reduced, and the thermoplastic resin composition is not practically usable. Furthermore, the compounding amount of the component (E) is
0.1 to 100 parts by weight of the total of component (A) and component (B)
It must be 2.0 parts by weight. If the component (E) is less than 0.1 part by weight, it will not sufficiently serve as a crosslinking initiator. On the other hand, when the component (E) exceeds 2.0 parts by weight, radicals are generated at locations other than the unsaturated bond site, which is not preferable.

Next, a method for producing the resin composition of the present invention will be described. Although the method of the present invention is not particularly limited, the reaction between the component (A) and the component (C) and the internal crosslinking reaction of the component (B) need to be performed during melt-kneading. Here, the internal crosslinking means that the double bond site of the component (B) is added to another double bond site of the component (B) by the component (E) which is a crosslinking initiator. Specifically, using a Banbury mixer, a roller kneader, a single-screw or multi-screw extruder, etc., the components (A), (B), (C) and (D) are melt-kneaded, After reacting the components (A) and (C), the component (E) is added, and the component (B) is dynamically cross-linked by melt-kneading the component (A) and the component (C). After melt kneading and sufficiently reacting the terminal carboxyl group of the component (A) with the epoxy group of the component (C), the components (B) and (D)
Add the components and continue melt kneading, then (E)
There is a method in which the component (B) is dynamically crosslinked internally by further melt-kneading the components, but the former is preferred in terms of productivity.

As for the conditions for melt kneading, the kneading temperature must be equal to or higher than the melting temperature of the continuous phase component (A).
It is preferably from 150 to 250 ° C, particularly preferably from 170 to 220 ° C. Further, the residence time of the entire melt kneading is preferably 30 seconds to 15 minutes, and the residence time (kneading time required for crosslinking) after adding the component (E) is preferably 15 seconds to 10 minutes. .

The resin composition contains various additives such as an antioxidant, a plasticizer, an antistatic agent, an ultraviolet absorber, a coloring agent, a foaming agent, a crystal nucleating agent, a flame retardant, and a flame retardant auxiliary. It can be appropriately blended within a range that does not impair the properties of the present invention.

[0017]

The thermoplastic polyester resin composition of the present invention comprises:
The component (A) and the component (B) are compatible via the component (C), and the component (B) can be finely dispersed in the component (A). Furthermore, due to internal crosslinking of component (B), component (B)
Even if the volume fraction is higher than the component (A), the component (A) can be a continuous phase. Further, since the component (B) is cross-linked, rubber elasticity is more easily developed. further,
It is presumed that the addition of the component (D) causes the crosslinked component (B) to swell and become flexible, thereby obtaining an elastic thermoplastic resin composition having a low hardness as a whole.

[0018]

Next, the present invention will be described more specifically with reference to examples. In addition, the measuring method of each property value in an Example and a comparative example is as follows. (1) Surface hardness Measured according to JIS K-6301 A type. (2) Tensile strength and elongation Measured according to ASTM-D638.

Example 1 As a component (A), a random copolymerized polyester having a terephthalic acid / sebacic acid / tetramethylene glycol ratio of 80/20/100 (weight ratio) (relative viscosity 1.65, melting point 180 ° C.,
Terminal COOH number 79 eq / t) 50 parts by weight, EPDM rubber (“VISTALON 3708P” (registered trademark) manufactured by EXXON) 50 as a component (B) 50
Parts by weight, as the component (C), an olefin copolymer (ethylene-glycidyl methacrylate / vinyl acetate-based terpolymer (manufactured by Sumitomo Chemical Co., Ltd., “bondfast7B” (registered trademark), content of glycidyl methacrylate) : 12% by weight) and 10 parts by weight of a paraffinic oil ("STANOL69" (registered trademark), weight average molecular weight: 560) manufactured by Esso Petroleum Co., Ltd.) as the component (D), and twin-screw extrusion with an inner diameter of 30 mm. Kneading temperature 200 ° C using a machine (Ikegai Iron Works, PCM-30)
After melt-kneading under the conditions of a kneading time of 4 minutes, the component (A) and the component (C) are reacted to form a pellet, and then the component (E) 2,5-dimethyl-2,5-di- 0.48 parts by weight of (t-butylperoxy) hexyne-3 [manufactured by NOF CORPORATION, “Perhexin 25B” (registered trademark), white powder type] was added, and the kneading temperature was again 200 ° C. and kneading time was 2 minutes using a twin-screw extruder. The component (B) was internally kneaded by melt-kneading under the conditions described above to form a pellet. Next, these pellets are injected into an injection molding machine (Mitsubishi Heavy Industries,
(125/75 type). Table 1 shows the physical properties of the obtained test pieces.

Examples 2 to 5 and Comparative Examples 1 to 6 Except that the amounts of the components (A), (B), (C), (D) and (E) were changed as shown in Table 1, A test piece was prepared in the same manner as in Example 1. Table 1 shows the physical properties of the obtained test pieces.

[0021]

[Table 1]

The resin compositions obtained in Examples 1 to 5 were able to obtain excellent values in all of physical properties such as surface hardness, tensile strength and elongation. In contrast, the comparative example has the following problem.

In Comparative Example 1, no dynamic internal crosslinking was performed, and the component (C) as a compatibilizer was not present.
The compatibility between the component (A) and the component (B) was poor, the tensile strength and elongation were remarkably poor, and the product was not practical. Comparative Example 2
Was an elastomer having high hardness and inferior flexibility because no component (D) was added. Further, the discharge pressure at the time of molding was extremely high, and molding irregularities were formed, resulting in poor operation stability. Comparative Example 3 was an elastomer having high hardness and inferior flexibility because it was only a random copolymerized polyester. Comparative Example 4, which was a sample subjected to dynamic internal crosslinking, had a high hardness and was inferior in flexibility due to a large amount of component (A) serving as a matrix.
In Comparative Example 5, since the amount of the component (C) was too large, the mold releasability during molding was poor, and the surface of the molded product was tacky. In addition, the cost was high, which was not preferable. In Comparative Example 6, since the component (D) was too much, the tensile strength was remarkably inferior and was not practical.

[0024]

According to the present invention, it is possible to easily impart low hardness and flexibility while maintaining the thermoplasticity and moldability of the conventional TPEE. It can also be applied to fields that were advantageous.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 31/04 C08L 31/04 33/14 33/14 67/02 67/02

Claims (4)

[Claims] 1. A random copolymerized polyester resin (A)
Total of 75 to 5 parts by weight and (B) 25 to 95 parts by weight of EPDM rubber 100
(C) 1 to 20 parts by weight of an olefin copolymer having at least an epoxy-containing (meth) acrylate component in the same molecule, and (D) 1 to 20 parts by weight of paraffinic oil based on parts by weight.
A thermoplastic polyester resin composition characterized by being mixed with 0.1 part by weight and (E) 0.1 to 2.0 parts by weight of a crosslinking initiator. 2. The olefin copolymer of component (C) is an ethylene / glycidyl (meth) acrylate copolymer, a propylene / glycidyl (meth) acrylate copolymer,
Ethylene / glycidyl (meth) acrylate / vinyl acetate terpolymer, propylene / glycidyl (meth) acrylate / vinyl acetate terpolymer, ethylene / propylene / glycidyl (meth) acrylate / vinyl acetate quaternary 2. The thermoplastic polyester resin composition according to claim 1, comprising an olefin copolymer selected from the group consisting of polymers. 3. The thermoplastic polyester resin composition according to claim 1, wherein the paraffinic oil as the component (D) has a weight average molecular weight in the range of 300 to 730. 4. A random copolymerized polyester resin, (B) an EPDM rubber, (C) an olefin copolymer having at least an epoxy-containing (meth) acrylate component in the same molecule, and (D) a paraffinic oil. Melt kneading,
After the component (A) and the component (C) are reacted, (E) a crosslinking initiator is added, and the component (B) is internally crosslinked by melt-kneading, thereby producing a thermoplastic polyester resin composition. .